Merge pull request #1812 from dagar/appveyor

appveyor support (windows ci)

.appveyor.yml

+
+environment:
+  matrix:
+  - BUILD: 'Release'
+    CONFIG: release
+  - BUILD: 'Debug'
+    CONFIG: debug
+
+install:
+  - git submodule update --init --recursive
+  - call "%ProgramFiles(x86)%\Microsoft Visual Studio 12.0\VC\vcvarsall.bat" x86
+  - set PATH=C:\Qt\Tools\QtCreator\bin;C:\Qt\5.4\msvc2013_opengl\bin;%PATH%
+  - mkdir %LOCALAPPDATA%\QtProject && copy test\qtlogging.ini %LOCALAPPDATA%\QtProject\
+
+build_script:
+   - C:\Qt\5.4\msvc2013_opengl\bin\qmake -r CONFIG-=debug_and_release CONFIG+=%CONFIG% CONFIG+=WarningsAsErrorsOn qgroundcontrol.pro
+   - jom -j 2
+
+test_script:
+#  - if "%CONFIG%" EQU "debug" ( debug\qgroundcontrol --unittest )
+